\begin{tikzpicture}
 \begin{axis}[
 width=.7\textwidth,
 height = 10cm,
 xlabel = Emissions,
 ylabel = MAC,
  xmin=0,xmax=5,
  ymin=0,ymax=4,
  clip=false,
  enlargelimits=true,
  axis lines= middle,
 ymajorgrids=false,
 xmajorgrids=false,
 ticks=none,
 %axis x line=bottom,
 %axis y line=middle,
  xlabel style={
    anchor=north
  },
  ylabel style={
    anchor=east
  },
 ylabel style={anchor=west},
 grid style=dashed,
 legend style={font=\medium},
 legend cell align=left,
 legend pos=north east
  ]
    
    \addplot+[const plot, no marks, thick, black, dashed] coordinates {(1, 0) (1,3.6)};
    \node at (axis cs:1,-.2) {\small $E^{\text{min}}_i$};
    \addplot+[const plot, no marks, thick, black, dashed] coordinates {(3.5, 0) (3.5,3.6)};
    \node at (axis cs:3.5,-.2) {\small $E^{\text{max}}_i$};
    \addplot+[const plot, no marks, thick, black, dashed] coordinates {(0, 2) (5,2)};
    \node at (axis cs:-.2,2) {\small $\xi_{it}$};
    
    \addplot+[const plot, no marks, thick, blue] coordinates {(1,3.6) (1,2)  (3.5,2) (3.5,0) (5,0)};

\end{axis}
\end{tikzpicture}